Improved Neutralisation of the SARS-CoV-2 Omicron Variant following a Booster Dose of Pfizer-BioNTech (BNT162b2) COVID-19 Vaccine

Viruses. 2022 Sep 13;14(9):2023. doi: 10.3390/v14092023.


In late November 2021, the World Health Organization declared the SARS-CoV-2 lineage B.1.1.529 the fifth variant of concern, Omicron. This variant has acquired over 30 mutations in the spike protein (with 15 in the receptor-binding domain), raising concerns that Omicron could evade naturally acquired and vaccine-derived immunity. We utilized an authentic virus, multicycle neutralisation assay to demonstrate that sera collected one, three, and six months post-two doses of Pfizer-BioNTech BNT162b2 had a limited ability to neutralise SARS-CoV-2. However, four weeks after a third dose, neutralising antibody titres were boosted. Despite this increase, neutralising antibody titres were reduced fourfold for Omicron compared to lineage A.2.2 SARS-CoV-2.

Keywords: COVID-19; Omicron; Pfizer-BioNTech BNT162b2; SARS-CoV-2; VOC; immunity; neutralising antibodies; vaccine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Neutralizing
  • Antibodies, Viral
  • BNT162 Vaccine
  • COVID-19 Vaccines
  • COVID-19* / prevention & control
  • Humans
  • SARS-CoV-2 / genetics
  • Spike Glycoprotein, Coronavirus / genetics
  • Vaccines*
  • Viral Envelope Proteins / genetics


  • Antibodies, Neutralizing
  • Antibodies, Viral
  • COVID-19 Vaccines
  • Spike Glycoprotein, Coronavirus
  • Vaccines
  • Viral Envelope Proteins
  • spike protein, SARS-CoV-2
  • BNT162 Vaccine

Supplementary concepts

  • SARS-CoV-2 variants

Grants and funding

This study was supported by the Prevention Research Support Program funded by the NSW Ministry of Health, NSW Health COVID-19 priority funding, and the National Health and Medical Research Council, Australia (APPRISE 1116530). Basile is supported by a Jerry Koutts PhD Scholarship from the Institute of Clinical Pathology and Medical Research Trust Fund.